Well, ahem, they were there to protect the relief personnel, NOT the locals. And what the UN failed to do in Serb-controlled Croatia in 1995, they ALSO failed to do in Srebrenica in what became Serb-controlled Bosnia in 1995 as well. So don't complain. The very fecklessness that allowed the Croats to get away with it in Knin ALSO allowed YOU GUYS to get away with Kravica.
The utter fecklessness of the EU/UN piecekeepers is well known. But one thing for DAMN sure: EVERYONE in Bosnia knew not to screw with the United States--we're such crazy cowboys that nobody dared to take us on.
Is that so difficult to understand for you?
Okay, I'll take the bait. Though it requires a quick review of Yugohistory. I'll give it a shot.
Yugoslavia was a "constitutive kingdom" when founded in a mutual love feast between Serbs and Croats in 1918 (the international equivalent of two drunken lovers having a night of really great sex and then getting married the next morning before they sober up). The kingdom was, in point of fact, a mini-Serb empire, a reward to Serbia by the Western allies for what it suffered at the hands of the Hungarians. Croat, Slovenia, and a chunk of what had been Hungary was given to Serbia, as well as a piece of Bulgaria and the formerly-Austrian controlled Bosnia. The Serb king became the king of all of the Kingdom-of-Serbs-Croats-Slovenes-And-A-Bunch-Of-Minorities-Whose-Existence-They-Did-Not-Deem-Worthy-of-Mention-Because-We're-More-Important-Than-They-Are.
What it really was, though, was a mini-Serb empire. The Croats and Slovenes discovered that their marriage to the Serbs meant rule by a Serb king, a Serb bureaucracy, a Serb army, and a Serb-dominated national assembly. Naturally, they decided they didn't like it very much.
In 1929, the Serb kingdom decided that a foot-long official name was unwieldy (they had to print their currency on butcher paper to fit it all in) so they shortened it to "The Kingdom of Yugoslavia." The Serb king (Peter I? one forgets) decided to abolish all the internal provincial identities and impose "banovinas" (governorships) to try to suppress local nationalist pressures. Didn't work; the Serb king was shot by Croatian Nazis in '34, replaced by his 11 year old son, and by 1940 Yugoslavia was on the brink of civil war all on its own.
Then Hitler showed up and the whole thing fell into a byzantine mess. The Croats declared independence and became a Nazi minor ally; the Serbs were occupied by the Germans; the rest of the territories were carved up like a Christmas turkey and served to the neighbors.
The Serbs, I'll say, DO have a legitimate beef with the Croats' cooperation with the Germans in War Two, and a hell of a lot of them DID die at the hands of the (REAL!) Ustashe in 1940-1945. The Croats, who were the villains of THAT war, built a death camp at Jasanovac and killed a hell of a lot of Serbs (whether 70,000, 700,000, or some number in between will not be revealed to us in this life).
A three sided civil war then broke out, between the Ustashe in Croatia, the Chetniks in Serbia, and the Partisan Communists all over. The Partisans of course gained the upper hand through military victory, skilled diplomacy with the Allies, and a number of stupid moves made by the Chetniks in particular (involving temporary cooperation with surrendering Italian Fascists that got misinterpreted by the wrong parties in London).
"Modern" Yugoslavia, founded in 1943, was absolutely a bastard Communist construct from the beginning of its reemegence. It was entirely artificial and a Communist creation. The Communists built the state on a pile of skulls, 300,000 or so executed after the war. Most of the skulls were Croatian Ustashe, but a lot of them were Serb Chetnik skulls as well. Throughout the 1940s and 1950s nationalism was suppressed and the state was maintained through a secret police force. The chant "Bratsvo i edinstvo" (Brotherhood and Unity) and a political correctness that would make you gag with disbelief was used to drown out any nationalist sentiment at all.
Then Tito died, and the system began to die as well, in 1980.
As the Commie party began to rot after Tito died, the Serbs saw this as a chance to reimpose the old Serb-dominated order, less the royalty. The beginning of this was the entirely artificial sense of "crisis" over the situation in Kosovo. Slobo, in 1988+, started to suck up to Serb nationalists in the province, crushed the local elected government (as well as that in the former Hungarian territories in Vojvodina) and reasserted Serb dominance over the Yugoslavian national government, given that four of the eight votes in the central counsel--Serbia, Voivodina, Kosovo, and allied almost-Serb Montenegro--were now in a unified voice.
Naturally, nobody else in Yugoslavia was really keen on being under the thumb of the Serbs. The Slovenes had seen the train coming for years and bolted at the first opportunity. The Serbs let them go; no Serbs live in Slovenia (or at least not all that many). But Croatia and Bosnia made for a different story.
The Croats only got on board the independence bandwagon about 1990 or so. When they decided to bolt, they were only half prepared. And Bosnia, which also bolted with Croatia, was COMPLETELY unprepared; Alia Izetbegovic trusted that Bosnia's status as an Internationally Recognized State would make it immune to Serb aggression. As Otter would say, "he ----ed up! He trusted us!"
So the upshot: Serbia, driven by old imperial fantasies, less old fears of Croatian genocide, and new fantasies of Muslim "aggression", decided to take as much of their neighboring territories as they could.
What was the Serb error?
Simple. The Serbs could not comprehend that the rest of the world, and particularly the Europeans, could not tolerate the concept of forced transfer of territory from one nation to another.
From the point of view of the world system of nation states, with the impending death of Yugoslavia as a state, authority then devolved down to its constituent republics. The international system is VERY committed to the maintenance of international borders. It is one thing for one nation to split into two, like Czechoslovakia--or in the case of the former Yugoslavia, into six. It is quite another thing to imagine that provinces can be grabbed from one country by another by force of arms. THAT is a grave threat to the international order; once that is allowed, the flood gates open to wars of miniaggression and irredentism worldwide. THAT is intolerable.
A Bosnia that has split into two might be tolerated; a Serbia that splits Bosnia into two and then eats one of the two halves is NOT.
So. Anything that protects the territorial integrity of nation states will be supported by the international community, the EU, the US, and the UN. In that, Alia Izetbegovic was not far wrong. HIS mistake was thinking we'd show up over the horizon on Day 1 and save his bacon. We weren't prepared to do that, until Srebrenica made ignoring the Bosnian problem intolerable.
What I'm saying is this: the old Yugoslav communist state's death was INEVITABLE with the death of the Communist party, since it was founded ab initio as a Communist state. Hence, claims to the 'constitutionality' of constituent state independence is inoperative. HOWEVER, the territorial integrity of each of the subordinate states of the former Yugoslavia MUST be preserved as much as possible, as the international order is based on the involiability of international borders. So Serbia was between a rock and a hard place. They didn't want to let Croatia and Bosnia and etc go, but had no legitimate claim on the whole of Croatia and Bosnia because the Communist system that had kept all the states together was as dead at Tito himself. On the other hand, Serbia tried to assert authority over cantons and opcinas of its neighbors, and that the international community could not tolerate. So it was a losing proposition.
Had Serbia and Croatia (leaving Bosnia aside for a moment) been ruled by Vlacev Havels or Mikhail Gorbachevs, there's a possibility the Yugoslav state could have been preserved or, more likely, an amiciable "velvet divorce" achieved. But NOOOOOOO. Serbia was ruled by the Nazi Milosevic, Croatia by the thug Tudjman, and Bosnia by the naive and romantic noodnik (albeit very sharp negotiator, as we discovered at Dayton) Izetbegovic.
So back to your question:
The Serbs in Croatia and Bosnia were Yugoslav citizens on Yugoslav soil at that time.
Unfortunately Yugoslavia had been founded by a thug party that was dead. Without the Communists, the state was as dead as Tito. Claims of any legitimate hold on that basis was inoperative. No one had the right to stripp them of their constitutional rights.
Well, they still retained their full measure of inalienable human rights. But the constitution that protected them was gone. They tried to replace it with claims of rank nationalism. Didn't work.
As Croatia and Bosnia-Hercegovina claimed the right to self-determination to seperate from Yugoslvia, the serbs of Krajina and Republika Srpska in response claimed their right to self-determination and secession from the newly created statelettes.
See above about the inviolability of international borders.
Is this ultimately the interference of outside powers in the affairs of the Balkans? Yep. Tough noogie. You guys want to sell Yugos to unsuspecting customers in other countries, that carries with it an obligation to play by Real World Rules under the international community. And that meant, ultimately, that Serb attempts to grab pieces of Croatia and Bosnia were intolerable to the rest of the world, and had to be stopped.
Okay, where does that argument leave what happend in Kosovo?
Well, we have a new factor, born in the ashes of WW2, and asserted in Bosnia: genocide and ethnic cleansing is become intolerable in Europe. We intervened in Bosnia when Sreb happened. We intervened in Kosovo when it became clear to us that a second Sreb was going to happen in Kosovo.
So where does the inviolability of national borders apply in Kosovo and Serbia?
Beats the hell out of me. My guess? Kosovo will eventually be either allowed to become independent or to federate very loosely with Serbia (just as Montenegro has just done). Whatever the solution, the International Community will never allow Albania to take Kosovo. That would violate the same rule about the sacredness of national borders mentioned above.
This is not the best of histories, I'll admit, but it sure beats chanting SUMASRPSKA while beating Muslims over the head with truncheons.